Contents of /tags/mkinitrd-6_1_3/busybox/init/init.c
Parent Directory | Revision Log
Revision 846 -
(show annotations)
(download)
Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
File MIME type: text/plain
File size: 25272 byte(s)
Mon May 4 18:51:23 2009 UTC (15 years, 4 months ago) by niro
File MIME type: text/plain
File size: 25272 byte(s)
tagged 'mkinitrd-6_1_3'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini init implementation for busybox |
4 | * |
5 | * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>. |
6 | * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
7 | * Adjusted by so many folks, it's impossible to keep track. |
8 | * |
9 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
10 | */ |
11 | |
12 | #include "libbb.h" |
13 | #include <syslog.h> |
14 | #include <paths.h> |
15 | #include <sys/reboot.h> |
16 | |
17 | /* Was a CONFIG_xxx option. A lot of people were building |
18 | * not fully functional init by switching it on! */ |
19 | #define DEBUG_INIT 0 |
20 | |
21 | #define COMMAND_SIZE 256 |
22 | #define CONSOLE_NAME_SIZE 32 |
23 | #define MAXENV 16 /* Number of env. vars */ |
24 | |
25 | /* |
26 | * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called |
27 | * before processes are spawned to set core file size as unlimited. |
28 | * This is for debugging only. Don't use this is production, unless |
29 | * you want core dumps lying about.... |
30 | */ |
31 | #define CORE_ENABLE_FLAG_FILE "/.init_enable_core" |
32 | #include <sys/resource.h> |
33 | |
34 | #define INITTAB "/etc/inittab" /* inittab file location */ |
35 | #ifndef INIT_SCRIPT |
36 | #define INIT_SCRIPT "/etc/init.d/rcS" /* Default sysinit script. */ |
37 | #endif |
38 | |
39 | /* Allowed init action types */ |
40 | #define SYSINIT 0x01 |
41 | #define RESPAWN 0x02 |
42 | /* like respawn, but wait for <Enter> to be pressed on tty: */ |
43 | #define ASKFIRST 0x04 |
44 | #define WAIT 0x08 |
45 | #define ONCE 0x10 |
46 | #define CTRLALTDEL 0x20 |
47 | #define SHUTDOWN 0x40 |
48 | #define RESTART 0x80 |
49 | |
50 | /* Set up a linked list of init_actions, to be read from inittab */ |
51 | struct init_action { |
52 | struct init_action *next; |
53 | pid_t pid; |
54 | uint8_t action_type; |
55 | char terminal[CONSOLE_NAME_SIZE]; |
56 | char command[COMMAND_SIZE]; |
57 | }; |
58 | |
59 | /* Static variables */ |
60 | static struct init_action *init_action_list = NULL; |
61 | |
62 | static const char *log_console = VC_5; |
63 | |
64 | enum { |
65 | L_LOG = 0x1, |
66 | L_CONSOLE = 0x2, |
67 | |
68 | #if ENABLE_FEATURE_EXTRA_QUIET |
69 | MAYBE_CONSOLE = 0x0, |
70 | #else |
71 | MAYBE_CONSOLE = L_CONSOLE, |
72 | #endif |
73 | |
74 | #ifndef RB_HALT_SYSTEM |
75 | RB_HALT_SYSTEM = 0xcdef0123, /* FIXME: this overflows enum */ |
76 | RB_ENABLE_CAD = 0x89abcdef, |
77 | RB_DISABLE_CAD = 0, |
78 | RB_POWER_OFF = 0x4321fedc, |
79 | RB_AUTOBOOT = 0x01234567, |
80 | #endif |
81 | }; |
82 | |
83 | /* Function prototypes */ |
84 | static void halt_reboot_pwoff(int sig) NORETURN; |
85 | |
86 | static void waitfor(pid_t pid) |
87 | { |
88 | /* waitfor(run(x)): protect against failed fork inside run() */ |
89 | if (pid <= 0) |
90 | return; |
91 | |
92 | /* Wait for any child (prevent zombies from exiting orphaned processes) |
93 | * but exit the loop only when specified one has exited. */ |
94 | while (wait(NULL) != pid) |
95 | continue; |
96 | } |
97 | |
98 | static void loop_forever(void) NORETURN; |
99 | static void loop_forever(void) |
100 | { |
101 | while (1) |
102 | sleep(1); |
103 | } |
104 | |
105 | /* Print a message to the specified device. |
106 | * "where" may be bitwise-or'd from L_LOG | L_CONSOLE |
107 | * NB: careful, we can be called after vfork! |
108 | */ |
109 | #define messageD(...) do { if (DEBUG_INIT) message(__VA_ARGS__); } while (0) |
110 | static void message(int where, const char *fmt, ...) |
111 | __attribute__ ((format(printf, 2, 3))); |
112 | static void message(int where, const char *fmt, ...) |
113 | { |
114 | static int log_fd = -1; |
115 | va_list arguments; |
116 | unsigned l; |
117 | char msg[128]; |
118 | |
119 | msg[0] = '\r'; |
120 | va_start(arguments, fmt); |
121 | l = 1 + vsnprintf(msg + 1, sizeof(msg) - 2, fmt, arguments); |
122 | if (l > sizeof(msg) - 1) |
123 | l = sizeof(msg) - 1; |
124 | msg[l] = '\0'; |
125 | va_end(arguments); |
126 | |
127 | if (ENABLE_FEATURE_INIT_SYSLOG) { |
128 | if (where & L_LOG) { |
129 | /* Log the message to syslogd */ |
130 | openlog("init", 0, LOG_DAEMON); |
131 | /* don't print "\r" */ |
132 | syslog(LOG_INFO, "%s", msg + 1); |
133 | closelog(); |
134 | } |
135 | msg[l++] = '\n'; |
136 | msg[l] = '\0'; |
137 | } else { |
138 | msg[l++] = '\n'; |
139 | msg[l] = '\0'; |
140 | /* Take full control of the log tty, and never close it. |
141 | * It's mine, all mine! Muhahahaha! */ |
142 | if (log_fd < 0) { |
143 | if (!log_console) { |
144 | log_fd = STDERR_FILENO; |
145 | } else { |
146 | log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY); |
147 | if (log_fd < 0) { |
148 | bb_error_msg("can't log to %s", log_console); |
149 | where = L_CONSOLE; |
150 | } else { |
151 | close_on_exec_on(log_fd); |
152 | } |
153 | } |
154 | } |
155 | if (where & L_LOG) { |
156 | full_write(log_fd, msg, l); |
157 | if (log_fd == STDERR_FILENO) |
158 | return; /* don't print dup messages */ |
159 | } |
160 | } |
161 | |
162 | if (where & L_CONSOLE) { |
163 | /* Send console messages to console so people will see them. */ |
164 | full_write(STDERR_FILENO, msg, l); |
165 | } |
166 | } |
167 | |
168 | /* From <linux/serial.h> */ |
169 | struct serial_struct { |
170 | int type; |
171 | int line; |
172 | unsigned int port; |
173 | int irq; |
174 | int flags; |
175 | int xmit_fifo_size; |
176 | int custom_divisor; |
177 | int baud_base; |
178 | unsigned short close_delay; |
179 | char io_type; |
180 | char reserved_char[1]; |
181 | int hub6; |
182 | unsigned short closing_wait; /* time to wait before closing */ |
183 | unsigned short closing_wait2; /* no longer used... */ |
184 | unsigned char *iomem_base; |
185 | unsigned short iomem_reg_shift; |
186 | unsigned int port_high; |
187 | unsigned long iomap_base; /* cookie passed into ioremap */ |
188 | int reserved[1]; |
189 | /* Paranoia (imagine 64bit kernel overwriting 32bit userspace stack) */ |
190 | uint32_t bbox_reserved[16]; |
191 | }; |
192 | static void console_init(void) |
193 | { |
194 | struct serial_struct sr; |
195 | char *s; |
196 | |
197 | s = getenv("CONSOLE"); |
198 | if (!s) |
199 | s = getenv("console"); |
200 | if (s) { |
201 | int fd = open(s, O_RDWR | O_NONBLOCK | O_NOCTTY); |
202 | if (fd >= 0) { |
203 | dup2(fd, STDIN_FILENO); |
204 | dup2(fd, STDOUT_FILENO); |
205 | xmove_fd(fd, STDERR_FILENO); |
206 | } |
207 | messageD(L_LOG, "console='%s'", s); |
208 | } else { |
209 | /* Make sure fd 0,1,2 are not closed |
210 | * (so that they won't be used by future opens) */ |
211 | bb_sanitize_stdio(); |
212 | // Users report problems |
213 | // /* Make sure init can't be blocked by writing to stderr */ |
214 | // fcntl(STDERR_FILENO, F_SETFL, fcntl(STDERR_FILENO, F_GETFL) | O_NONBLOCK); |
215 | } |
216 | |
217 | s = getenv("TERM"); |
218 | if (ioctl(STDIN_FILENO, TIOCGSERIAL, &sr) == 0) { |
219 | /* Force the TERM setting to vt102 for serial console |
220 | * if TERM is set to linux (the default) */ |
221 | if (!s || strcmp(s, "linux") == 0) |
222 | putenv((char*)"TERM=vt102"); |
223 | if (!ENABLE_FEATURE_INIT_SYSLOG) |
224 | log_console = NULL; |
225 | } else if (!s) |
226 | putenv((char*)"TERM=linux"); |
227 | } |
228 | |
229 | /* Set terminal settings to reasonable defaults. |
230 | * NB: careful, we can be called after vfork! */ |
231 | static void set_sane_term(void) |
232 | { |
233 | struct termios tty; |
234 | |
235 | tcgetattr(STDIN_FILENO, &tty); |
236 | |
237 | /* set control chars */ |
238 | tty.c_cc[VINTR] = 3; /* C-c */ |
239 | tty.c_cc[VQUIT] = 28; /* C-\ */ |
240 | tty.c_cc[VERASE] = 127; /* C-? */ |
241 | tty.c_cc[VKILL] = 21; /* C-u */ |
242 | tty.c_cc[VEOF] = 4; /* C-d */ |
243 | tty.c_cc[VSTART] = 17; /* C-q */ |
244 | tty.c_cc[VSTOP] = 19; /* C-s */ |
245 | tty.c_cc[VSUSP] = 26; /* C-z */ |
246 | |
247 | /* use line discipline 0 */ |
248 | tty.c_line = 0; |
249 | |
250 | /* Make it be sane */ |
251 | tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD; |
252 | tty.c_cflag |= CREAD | HUPCL | CLOCAL; |
253 | |
254 | /* input modes */ |
255 | tty.c_iflag = ICRNL | IXON | IXOFF; |
256 | |
257 | /* output modes */ |
258 | tty.c_oflag = OPOST | ONLCR; |
259 | |
260 | /* local modes */ |
261 | tty.c_lflag = |
262 | ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHOCTL | ECHOKE | IEXTEN; |
263 | |
264 | tcsetattr_stdin_TCSANOW(&tty); |
265 | } |
266 | |
267 | /* Open the new terminal device. |
268 | * NB: careful, we can be called after vfork! */ |
269 | static void open_stdio_to_tty(const char* tty_name, int exit_on_failure) |
270 | { |
271 | /* empty tty_name means "use init's tty", else... */ |
272 | if (tty_name[0]) { |
273 | int fd; |
274 | close(STDIN_FILENO); |
275 | /* fd can be only < 0 or 0: */ |
276 | fd = device_open(tty_name, O_RDWR); |
277 | if (fd) { |
278 | message(L_LOG | L_CONSOLE, "can't open %s: %s", |
279 | tty_name, strerror(errno)); |
280 | if (exit_on_failure) |
281 | _exit(EXIT_FAILURE); |
282 | if (DEBUG_INIT) |
283 | _exit(2); |
284 | /* NB: we don't reach this if we were called after vfork. |
285 | * Thus halt_reboot_pwoff() itself need not be vfork-safe. */ |
286 | halt_reboot_pwoff(SIGUSR1); /* halt the system */ |
287 | } |
288 | dup2(STDIN_FILENO, STDOUT_FILENO); |
289 | dup2(STDIN_FILENO, STDERR_FILENO); |
290 | } |
291 | set_sane_term(); |
292 | } |
293 | |
294 | /* Wrapper around exec: |
295 | * Takes string (max COMMAND_SIZE chars). |
296 | * If chars like '>' detected, execs '[-]/bin/sh -c "exec ......."'. |
297 | * Otherwise splits words on whitespace, deals with leading dash, |
298 | * and uses plain exec(). |
299 | * NB: careful, we can be called after vfork! |
300 | */ |
301 | static void init_exec(const char *command) |
302 | { |
303 | char *cmd[COMMAND_SIZE / 2]; |
304 | char buf[COMMAND_SIZE + 6]; /* COMMAND_SIZE+strlen("exec ")+1 */ |
305 | int dash = (command[0] == '-' /* maybe? && command[1] == '/' */); |
306 | |
307 | /* See if any special /bin/sh requiring characters are present */ |
308 | if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) { |
309 | strcpy(buf, "exec "); |
310 | strcpy(buf + 5, command + dash); /* excluding "-" */ |
311 | /* NB: LIBBB_DEFAULT_LOGIN_SHELL define has leading dash */ |
312 | cmd[0] = (char*)(LIBBB_DEFAULT_LOGIN_SHELL + !dash); |
313 | cmd[1] = (char*)"-c"; |
314 | cmd[2] = buf; |
315 | cmd[3] = NULL; |
316 | } else { |
317 | /* Convert command (char*) into cmd (char**, one word per string) */ |
318 | char *word, *next; |
319 | int i = 0; |
320 | next = strcpy(buf, command); /* including "-" */ |
321 | while ((word = strsep(&next, " \t")) != NULL) { |
322 | if (*word != '\0') { /* not two spaces/tabs together? */ |
323 | cmd[i] = word; |
324 | i++; |
325 | } |
326 | } |
327 | cmd[i] = NULL; |
328 | } |
329 | /* If we saw leading "-", it is interactive shell. |
330 | * Try harder to give it a controlling tty. |
331 | * And skip "-" in actual exec call. */ |
332 | if (dash) { |
333 | /* _Attempt_ to make stdin a controlling tty. */ |
334 | if (ENABLE_FEATURE_INIT_SCTTY) |
335 | ioctl(STDIN_FILENO, TIOCSCTTY, 0 /*only try, don't steal*/); |
336 | } |
337 | BB_EXECVP(cmd[0] + dash, cmd); |
338 | message(L_LOG | L_CONSOLE, "cannot run '%s': %s", cmd[0], strerror(errno)); |
339 | /* returns if execvp fails */ |
340 | } |
341 | |
342 | /* Used only by run_actions */ |
343 | static pid_t run(const struct init_action *a) |
344 | { |
345 | pid_t pid; |
346 | sigset_t nmask, omask; |
347 | |
348 | /* Block sigchild while forking (why?) */ |
349 | sigemptyset(&nmask); |
350 | sigaddset(&nmask, SIGCHLD); |
351 | sigprocmask(SIG_BLOCK, &nmask, &omask); |
352 | if (BB_MMU && (a->action_type & ASKFIRST)) |
353 | pid = fork(); |
354 | else |
355 | pid = vfork(); |
356 | sigprocmask(SIG_SETMASK, &omask, NULL); |
357 | |
358 | if (pid < 0) |
359 | message(L_LOG | L_CONSOLE, "can't fork"); |
360 | if (pid) |
361 | return pid; |
362 | |
363 | /* Child */ |
364 | |
365 | /* Reset signal handlers that were set by the parent process */ |
366 | bb_signals(0 |
367 | + (1 << SIGUSR1) |
368 | + (1 << SIGUSR2) |
369 | + (1 << SIGINT) |
370 | + (1 << SIGTERM) |
371 | + (1 << SIGHUP) |
372 | + (1 << SIGQUIT) |
373 | + (1 << SIGCONT) |
374 | + (1 << SIGSTOP) |
375 | + (1 << SIGTSTP) |
376 | , SIG_DFL); |
377 | |
378 | /* Create a new session and make ourself the process |
379 | * group leader */ |
380 | setsid(); |
381 | |
382 | /* Open the new terminal device */ |
383 | open_stdio_to_tty(a->terminal, 1 /* - exit if open fails */); |
384 | |
385 | // NB: do not enable unless you change vfork to fork above |
386 | #ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING |
387 | /* If the init Action requires us to wait, then force the |
388 | * supplied terminal to be the controlling tty. */ |
389 | if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { |
390 | /* Now fork off another process to just hang around */ |
391 | pid = fork(); |
392 | if (pid < 0) { |
393 | message(L_LOG | L_CONSOLE, "can't fork"); |
394 | _exit(EXIT_FAILURE); |
395 | } |
396 | |
397 | if (pid > 0) { |
398 | /* Parent - wait till the child is done */ |
399 | bb_signals(0 |
400 | + (1 << SIGINT) |
401 | + (1 << SIGTSTP) |
402 | + (1 << SIGQUIT) |
403 | , SIG_IGN); |
404 | signal(SIGCHLD, SIG_DFL); |
405 | |
406 | waitfor(pid); |
407 | /* See if stealing the controlling tty back is necessary */ |
408 | if (tcgetpgrp(0) != getpid()) |
409 | _exit(EXIT_SUCCESS); |
410 | |
411 | /* Use a temporary process to steal the controlling tty. */ |
412 | pid = fork(); |
413 | if (pid < 0) { |
414 | message(L_LOG | L_CONSOLE, "can't fork"); |
415 | _exit(EXIT_FAILURE); |
416 | } |
417 | if (pid == 0) { |
418 | setsid(); |
419 | ioctl(0, TIOCSCTTY, 1); |
420 | _exit(EXIT_SUCCESS); |
421 | } |
422 | waitfor(pid); |
423 | _exit(EXIT_SUCCESS); |
424 | } |
425 | /* Child - fall though to actually execute things */ |
426 | } |
427 | #endif |
428 | |
429 | /* NB: on NOMMU we can't wait for input in child, so |
430 | * "askfirst" will work the same as "respawn". */ |
431 | if (BB_MMU && (a->action_type & ASKFIRST)) { |
432 | static const char press_enter[] ALIGN1 = |
433 | #ifdef CUSTOMIZED_BANNER |
434 | #include CUSTOMIZED_BANNER |
435 | #endif |
436 | "\nPlease press Enter to activate this console. "; |
437 | char c; |
438 | /* |
439 | * Save memory by not exec-ing anything large (like a shell) |
440 | * before the user wants it. This is critical if swap is not |
441 | * enabled and the system has low memory. Generally this will |
442 | * be run on the second virtual console, and the first will |
443 | * be allowed to start a shell or whatever an init script |
444 | * specifies. |
445 | */ |
446 | messageD(L_LOG, "waiting for enter to start '%s'" |
447 | "(pid %d, tty '%s')\n", |
448 | a->command, getpid(), a->terminal); |
449 | full_write(STDOUT_FILENO, press_enter, sizeof(press_enter) - 1); |
450 | while (safe_read(STDIN_FILENO, &c, 1) == 1 && c != '\n') |
451 | continue; |
452 | } |
453 | |
454 | if (ENABLE_FEATURE_INIT_COREDUMPS) { |
455 | struct stat sb; |
456 | if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) { |
457 | struct rlimit limit; |
458 | limit.rlim_cur = RLIM_INFINITY; |
459 | limit.rlim_max = RLIM_INFINITY; |
460 | setrlimit(RLIMIT_CORE, &limit); |
461 | } |
462 | } |
463 | |
464 | /* Log the process name and args */ |
465 | message(L_LOG, "starting pid %d, tty '%s': '%s'", |
466 | getpid(), a->terminal, a->command); |
467 | |
468 | /* Now run it. The new program will take over this PID, |
469 | * so nothing further in init.c should be run. */ |
470 | init_exec(a->command); |
471 | /* We're still here? Some error happened. */ |
472 | _exit(-1); |
473 | } |
474 | |
475 | static void delete_init_action(struct init_action *action) |
476 | { |
477 | struct init_action *a, *b = NULL; |
478 | |
479 | for (a = init_action_list; a; b = a, a = a->next) { |
480 | if (a == action) { |
481 | if (b == NULL) { |
482 | init_action_list = a->next; |
483 | } else { |
484 | b->next = a->next; |
485 | } |
486 | free(a); |
487 | break; |
488 | } |
489 | } |
490 | } |
491 | |
492 | /* Run all commands of a particular type */ |
493 | static void run_actions(int action_type) |
494 | { |
495 | struct init_action *a, *tmp; |
496 | |
497 | for (a = init_action_list; a; a = tmp) { |
498 | tmp = a->next; |
499 | if (a->action_type & action_type) { |
500 | // Pointless: run() will error out if open of device fails. |
501 | ///* a->terminal of "" means "init's console" */ |
502 | //if (a->terminal[0] && access(a->terminal, R_OK | W_OK)) { |
503 | // //message(L_LOG | L_CONSOLE, "Device %s cannot be opened in RW mode", a->terminal /*, strerror(errno)*/); |
504 | // delete_init_action(a); |
505 | //} else |
506 | if (a->action_type & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { |
507 | waitfor(run(a)); |
508 | delete_init_action(a); |
509 | } else if (a->action_type & ONCE) { |
510 | run(a); |
511 | delete_init_action(a); |
512 | } else if (a->action_type & (RESPAWN | ASKFIRST)) { |
513 | /* Only run stuff with pid==0. If they have |
514 | * a pid, that means it is still running */ |
515 | if (a->pid == 0) { |
516 | a->pid = run(a); |
517 | } |
518 | } |
519 | } |
520 | } |
521 | } |
522 | |
523 | static void init_reboot(unsigned long magic) |
524 | { |
525 | pid_t pid; |
526 | /* We have to fork here, since the kernel calls do_exit(EXIT_SUCCESS) in |
527 | * linux/kernel/sys.c, which can cause the machine to panic when |
528 | * the init process is killed.... */ |
529 | pid = vfork(); |
530 | if (pid == 0) { /* child */ |
531 | reboot(magic); |
532 | _exit(EXIT_SUCCESS); |
533 | } |
534 | waitfor(pid); |
535 | } |
536 | |
537 | static void kill_all_processes(void) |
538 | { |
539 | /* run everything to be run at "shutdown". This is done _prior_ |
540 | * to killing everything, in case people wish to use scripts to |
541 | * shut things down gracefully... */ |
542 | run_actions(SHUTDOWN); |
543 | |
544 | /* first disable all our signals */ |
545 | sigprocmask_allsigs(SIG_BLOCK); |
546 | |
547 | message(L_CONSOLE | L_LOG, "The system is going down NOW!"); |
548 | |
549 | /* Allow Ctrl-Alt-Del to reboot system. */ |
550 | init_reboot(RB_ENABLE_CAD); |
551 | |
552 | /* Send signals to every process _except_ pid 1 */ |
553 | message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "TERM"); |
554 | kill(-1, SIGTERM); |
555 | sync(); |
556 | sleep(1); |
557 | |
558 | message(L_CONSOLE | L_LOG, "Sending SIG%s to all processes", "KILL"); |
559 | kill(-1, SIGKILL); |
560 | sync(); |
561 | sleep(1); |
562 | } |
563 | |
564 | static void halt_reboot_pwoff(int sig) |
565 | { |
566 | const char *m = "halt"; |
567 | int rb; |
568 | |
569 | kill_all_processes(); |
570 | |
571 | rb = RB_HALT_SYSTEM; |
572 | if (sig == SIGTERM) { |
573 | m = "reboot"; |
574 | rb = RB_AUTOBOOT; |
575 | } else if (sig == SIGUSR2) { |
576 | m = "poweroff"; |
577 | rb = RB_POWER_OFF; |
578 | } |
579 | message(L_CONSOLE | L_LOG, "Requesting system %s", m); |
580 | /* allow time for last message to reach serial console */ |
581 | sleep(2); |
582 | init_reboot(rb); |
583 | loop_forever(); |
584 | } |
585 | |
586 | /* Handler for QUIT - exec "restart" action, |
587 | * else (no such action defined) do nothing */ |
588 | static void exec_restart_action(int sig UNUSED_PARAM) |
589 | { |
590 | struct init_action *a; |
591 | |
592 | for (a = init_action_list; a; a = a->next) { |
593 | if (a->action_type & RESTART) { |
594 | kill_all_processes(); |
595 | |
596 | /* unblock all signals (blocked in kill_all_processes()) */ |
597 | sigprocmask_allsigs(SIG_UNBLOCK); |
598 | |
599 | /* Open the new terminal device */ |
600 | open_stdio_to_tty(a->terminal, 0 /* - halt if open fails */); |
601 | |
602 | messageD(L_CONSOLE | L_LOG, "Trying to re-exec %s", a->command); |
603 | init_exec(a->command); |
604 | sleep(2); |
605 | init_reboot(RB_HALT_SYSTEM); |
606 | loop_forever(); |
607 | } |
608 | } |
609 | } |
610 | |
611 | static void ctrlaltdel_signal(int sig UNUSED_PARAM) |
612 | { |
613 | run_actions(CTRLALTDEL); |
614 | } |
615 | |
616 | /* The SIGCONT handler is set to record_signo(). |
617 | * It just sets bb_got_signal = SIGCONT. */ |
618 | |
619 | /* The SIGSTOP & SIGTSTP handler */ |
620 | static void stop_handler(int sig UNUSED_PARAM) |
621 | { |
622 | int saved_errno = errno; |
623 | |
624 | bb_got_signal = 0; |
625 | while (bb_got_signal == 0) |
626 | pause(); |
627 | |
628 | errno = saved_errno; |
629 | } |
630 | |
631 | static void new_init_action(uint8_t action_type, const char *command, const char *cons) |
632 | { |
633 | struct init_action *a, *last; |
634 | |
635 | // Why? |
636 | // if (strcmp(cons, bb_dev_null) == 0 && (action & ASKFIRST)) |
637 | // return; |
638 | |
639 | /* Append to the end of the list */ |
640 | for (a = last = init_action_list; a; a = a->next) { |
641 | /* don't enter action if it's already in the list, |
642 | * but do overwrite existing actions */ |
643 | if ((strcmp(a->command, command) == 0) |
644 | && (strcmp(a->terminal, cons) == 0) |
645 | ) { |
646 | a->action_type = action_type; |
647 | return; |
648 | } |
649 | last = a; |
650 | } |
651 | |
652 | a = xzalloc(sizeof(*a)); |
653 | if (last) { |
654 | last->next = a; |
655 | } else { |
656 | init_action_list = a; |
657 | } |
658 | a->action_type = action_type; |
659 | safe_strncpy(a->command, command, sizeof(a->command)); |
660 | safe_strncpy(a->terminal, cons, sizeof(a->terminal)); |
661 | messageD(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", |
662 | a->command, a->action_type, a->terminal); |
663 | } |
664 | |
665 | /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined, |
666 | * then parse_inittab() simply adds in some default |
667 | * actions(i.e., runs INIT_SCRIPT and then starts a pair |
668 | * of "askfirst" shells). If CONFIG_FEATURE_USE_INITTAB |
669 | * _is_ defined, but /etc/inittab is missing, this |
670 | * results in the same set of default behaviors. |
671 | */ |
672 | static void parse_inittab(void) |
673 | { |
674 | #if ENABLE_FEATURE_USE_INITTAB |
675 | char *token[4]; |
676 | parser_t *parser = config_open2("/etc/inittab", fopen_for_read); |
677 | |
678 | if (parser == NULL) |
679 | #endif |
680 | { |
681 | /* No inittab file -- set up some default behavior */ |
682 | /* Reboot on Ctrl-Alt-Del */ |
683 | new_init_action(CTRLALTDEL, "reboot", ""); |
684 | /* Umount all filesystems on halt/reboot */ |
685 | new_init_action(SHUTDOWN, "umount -a -r", ""); |
686 | /* Swapoff on halt/reboot */ |
687 | if (ENABLE_SWAPONOFF) |
688 | new_init_action(SHUTDOWN, "swapoff -a", ""); |
689 | /* Prepare to restart init when a QUIT is received */ |
690 | new_init_action(RESTART, "init", ""); |
691 | /* Askfirst shell on tty1-4 */ |
692 | new_init_action(ASKFIRST, bb_default_login_shell, ""); |
693 | //TODO: VC_1 instead of ""? "" is console -> ctty problems -> angry users |
694 | new_init_action(ASKFIRST, bb_default_login_shell, VC_2); |
695 | new_init_action(ASKFIRST, bb_default_login_shell, VC_3); |
696 | new_init_action(ASKFIRST, bb_default_login_shell, VC_4); |
697 | /* sysinit */ |
698 | new_init_action(SYSINIT, INIT_SCRIPT, ""); |
699 | return; |
700 | } |
701 | |
702 | #if ENABLE_FEATURE_USE_INITTAB |
703 | /* optional_tty:ignored_runlevel:action:command |
704 | * Delims are not to be collapsed and need exactly 4 tokens |
705 | */ |
706 | while (config_read(parser, token, 4, 0, "#:", |
707 | PARSE_NORMAL & ~(PARSE_TRIM | PARSE_COLLAPSE))) { |
708 | /* order must correspond to SYSINIT..RESTART constants */ |
709 | static const char actions[] ALIGN1 = |
710 | "sysinit\0""respawn\0""askfirst\0""wait\0""once\0" |
711 | "ctrlaltdel\0""shutdown\0""restart\0"; |
712 | int action; |
713 | char *tty = token[0]; |
714 | |
715 | if (!token[3]) /* less than 4 tokens */ |
716 | goto bad_entry; |
717 | action = index_in_strings(actions, token[2]); |
718 | if (action < 0 || !token[3][0]) /* token[3]: command */ |
719 | goto bad_entry; |
720 | /* turn .*TTY -> /dev/TTY */ |
721 | if (tty[0]) { |
722 | if (strncmp(tty, "/dev/", 5) == 0) |
723 | tty += 5; |
724 | tty = concat_path_file("/dev/", tty); |
725 | } |
726 | new_init_action(1 << action, token[3], tty); |
727 | if (tty[0]) |
728 | free(tty); |
729 | continue; |
730 | bad_entry: |
731 | message(L_LOG | L_CONSOLE, "Bad inittab entry at line %d", |
732 | parser->lineno); |
733 | } |
734 | config_close(parser); |
735 | #endif |
736 | } |
737 | |
738 | #if ENABLE_FEATURE_USE_INITTAB |
739 | static void reload_signal(int sig UNUSED_PARAM) |
740 | { |
741 | struct init_action *a, *tmp; |
742 | |
743 | message(L_LOG, "reloading /etc/inittab"); |
744 | |
745 | /* disable old entrys */ |
746 | for (a = init_action_list; a; a = a->next) { |
747 | a->action_type = ONCE; |
748 | } |
749 | |
750 | parse_inittab(); |
751 | |
752 | if (ENABLE_FEATURE_KILL_REMOVED) { |
753 | /* Be nice and send SIGTERM first */ |
754 | for (a = init_action_list; a; a = a->next) { |
755 | pid_t pid = a->pid; |
756 | if ((a->action_type & ONCE) && pid != 0) { |
757 | kill(pid, SIGTERM); |
758 | } |
759 | } |
760 | #if CONFIG_FEATURE_KILL_DELAY |
761 | /* NB: parent will wait in NOMMU case */ |
762 | if ((BB_MMU ? fork() : vfork()) == 0) { /* child */ |
763 | sleep(CONFIG_FEATURE_KILL_DELAY); |
764 | for (a = init_action_list; a; a = a->next) { |
765 | pid_t pid = a->pid; |
766 | if ((a->action_type & ONCE) && pid != 0) { |
767 | kill(pid, SIGKILL); |
768 | } |
769 | } |
770 | _exit(EXIT_SUCCESS); |
771 | } |
772 | #endif |
773 | } |
774 | |
775 | /* remove unused entrys */ |
776 | for (a = init_action_list; a; a = tmp) { |
777 | tmp = a->next; |
778 | if ((a->action_type & (ONCE | SYSINIT | WAIT)) && a->pid == 0) { |
779 | delete_init_action(a); |
780 | } |
781 | } |
782 | run_actions(RESPAWN | ASKFIRST); |
783 | } |
784 | #endif |
785 | |
786 | int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
787 | int init_main(int argc UNUSED_PARAM, char **argv) |
788 | { |
789 | struct init_action *a; |
790 | pid_t wpid; |
791 | |
792 | die_sleep = 30 * 24*60*60; /* if xmalloc will ever die... */ |
793 | |
794 | if (argv[1] && !strcmp(argv[1], "-q")) { |
795 | return kill(1, SIGHUP); |
796 | } |
797 | |
798 | if (!DEBUG_INIT) { |
799 | /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */ |
800 | if (getpid() != 1 |
801 | && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc")) |
802 | ) { |
803 | bb_show_usage(); |
804 | } |
805 | /* Set up sig handlers -- be sure to |
806 | * clear all of these in run() */ |
807 | signal(SIGQUIT, exec_restart_action); |
808 | bb_signals(0 |
809 | + (1 << SIGUSR1) /* halt */ |
810 | + (1 << SIGUSR2) /* poweroff */ |
811 | + (1 << SIGTERM) /* reboot */ |
812 | , halt_reboot_pwoff); |
813 | signal(SIGINT, ctrlaltdel_signal); |
814 | signal(SIGCONT, record_signo); |
815 | bb_signals(0 |
816 | + (1 << SIGSTOP) |
817 | + (1 << SIGTSTP) |
818 | , stop_handler); |
819 | |
820 | /* Turn off rebooting via CTL-ALT-DEL -- we get a |
821 | * SIGINT on CAD so we can shut things down gracefully... */ |
822 | init_reboot(RB_DISABLE_CAD); |
823 | } |
824 | |
825 | /* Figure out where the default console should be */ |
826 | console_init(); |
827 | set_sane_term(); |
828 | xchdir("/"); |
829 | setsid(); |
830 | |
831 | /* Make sure environs is set to something sane */ |
832 | putenv((char *) "HOME=/"); |
833 | putenv((char *) bb_PATH_root_path); |
834 | putenv((char *) "SHELL=/bin/sh"); |
835 | putenv((char *) "USER=root"); /* needed? why? */ |
836 | |
837 | if (argv[1]) |
838 | xsetenv("RUNLEVEL", argv[1]); |
839 | |
840 | /* Hello world */ |
841 | message(MAYBE_CONSOLE | L_LOG, "init started: %s", bb_banner); |
842 | |
843 | /* Make sure there is enough memory to do something useful. */ |
844 | if (ENABLE_SWAPONOFF) { |
845 | struct sysinfo info; |
846 | |
847 | if (!sysinfo(&info) && |
848 | (info.mem_unit ? : 1) * (long long)info.totalram < 1024*1024) |
849 | { |
850 | message(L_CONSOLE, "Low memory, forcing swapon"); |
851 | /* swapon -a requires /proc typically */ |
852 | new_init_action(SYSINIT, "mount -t proc proc /proc", ""); |
853 | /* Try to turn on swap */ |
854 | new_init_action(SYSINIT, "swapon -a", ""); |
855 | run_actions(SYSINIT); /* wait and removing */ |
856 | } |
857 | } |
858 | |
859 | /* Check if we are supposed to be in single user mode */ |
860 | if (argv[1] |
861 | && (!strcmp(argv[1], "single") || !strcmp(argv[1], "-s") || LONE_CHAR(argv[1], '1')) |
862 | ) { |
863 | /* ??? shouldn't we set RUNLEVEL="b" here? */ |
864 | /* Start a shell on console */ |
865 | new_init_action(RESPAWN, bb_default_login_shell, ""); |
866 | } else { |
867 | /* Not in single user mode -- see what inittab says */ |
868 | |
869 | /* NOTE that if CONFIG_FEATURE_USE_INITTAB is NOT defined, |
870 | * then parse_inittab() simply adds in some default |
871 | * actions(i.e., runs INIT_SCRIPT and then starts a pair |
872 | * of "askfirst" shells */ |
873 | parse_inittab(); |
874 | } |
875 | |
876 | #if ENABLE_SELINUX |
877 | if (getenv("SELINUX_INIT") == NULL) { |
878 | int enforce = 0; |
879 | |
880 | putenv((char*)"SELINUX_INIT=YES"); |
881 | if (selinux_init_load_policy(&enforce) == 0) { |
882 | BB_EXECVP(argv[0], argv); |
883 | } else if (enforce > 0) { |
884 | /* SELinux in enforcing mode but load_policy failed */ |
885 | message(L_CONSOLE, "cannot load SELinux Policy. " |
886 | "Machine is in enforcing mode. Halting now."); |
887 | exit(EXIT_FAILURE); |
888 | } |
889 | } |
890 | #endif /* CONFIG_SELINUX */ |
891 | |
892 | /* Make the command line just say "init" - thats all, nothing else */ |
893 | strncpy(argv[0], "init", strlen(argv[0])); |
894 | /* Wipe argv[1]-argv[N] so they don't clutter the ps listing */ |
895 | while (*++argv) |
896 | memset(*argv, 0, strlen(*argv)); |
897 | |
898 | /* Now run everything that needs to be run */ |
899 | |
900 | /* First run the sysinit command */ |
901 | run_actions(SYSINIT); |
902 | |
903 | /* Next run anything that wants to block */ |
904 | run_actions(WAIT); |
905 | |
906 | /* Next run anything to be run only once */ |
907 | run_actions(ONCE); |
908 | |
909 | /* Redefine SIGHUP to reread /etc/inittab */ |
910 | #if ENABLE_FEATURE_USE_INITTAB |
911 | signal(SIGHUP, reload_signal); |
912 | #else |
913 | signal(SIGHUP, SIG_IGN); |
914 | #endif |
915 | |
916 | /* Now run the looping stuff for the rest of forever */ |
917 | while (1) { |
918 | /* run the respawn/askfirst stuff */ |
919 | run_actions(RESPAWN | ASKFIRST); |
920 | |
921 | /* Don't consume all CPU time -- sleep a bit */ |
922 | sleep(1); |
923 | |
924 | /* Wait for any child process to exit */ |
925 | wpid = wait(NULL); |
926 | while (wpid > 0) { |
927 | /* Find out who died and clean up their corpse */ |
928 | for (a = init_action_list; a; a = a->next) { |
929 | if (a->pid == wpid) { |
930 | /* Set the pid to 0 so that the process gets |
931 | * restarted by run_actions() */ |
932 | a->pid = 0; |
933 | message(L_LOG, "process '%s' (pid %d) exited. " |
934 | "Scheduling for restart.", |
935 | a->command, wpid); |
936 | } |
937 | } |
938 | /* see if anyone else is waiting to be reaped */ |
939 | wpid = wait_any_nohang(NULL); |
940 | } |
941 | } |
942 | } |